Image Forming Apparatus

ABSTRACT

An image forming apparatus includes a plurality of paper sheet feeders, a conveying unit, an image forming unit, and a control unit. The plurality of paper sheet feeders each include an opening/closing detection unit and a sheet information detecting unit. The opening/closing detection unit detects opening and closing of the paper sheet feeder. The sheet information detecting unit detects sheet information. The sheet information indicates information regarding a sheet housed in the paper sheet feeder. When the opening/closing detection unit detects that the paper sheet feeder is closed after detecting that the paper sheet feeder was opened, the control unit: determines whether the sheet information has changed from before and after opening and closing the paper sheet feeder or not, and determines whether to switch the selected paper sheet feeder or not based on the determination result.

INCORPORATION BY REFERENCE

This application is based upon, and claims the benefit of priority from, corresponding Japanese Patent Application No. 2018-094455 filed in the Japan Patent Office on May 16, 2018, the entire contents of which are incorporated herein by reference.

BACKGROUND

Unless otherwise indicated herein, the description in this section is not prior art to the claims in this application and is not admitted to be prior art by inclusion in this section.

An image forming apparatus usually includes a plurality of paper sheet feeders. The image forming apparatus performs an image formation by paper feeding a sheet from a paper sheet feeder selected among the plurality of paper sheet feeders.

SUMMARY

An image forming apparatus according to one aspect of the disclosure includes a plurality of paper sheet feeders, a conveying unit, an image forming unit, and a control unit. The plurality of paper sheet feeders are configured to each house sheets. The plurality of paper sheet feeders are openable/closable. The conveying unit conveys a sheet from a paper sheet feeder selected among the plurality of paper sheet feeders. The image forming unit forms an image on the sheet conveyed by the conveying unit. The control unit controls the paper sheet feeder, the image forming unit, and the conveying unit. The plurality of paper sheet feeders each include an opening/closing detection unit and a sheet information detecting unit. The opening/closing detection unit detects opening and closing of the paper sheet feeder. The sheet information detecting unit detects sheet information. The sheet information indicates information regarding a sheet housed in the paper sheet feeder. When the opening/closing detection unit detects that the paper sheet feeder is closed after detecting that the paper sheet feeder was opened, the control unit: determines whether the sheet information has changed from before and after opening and closing the paper sheet feeder or not, and determines whether to switch the selected paper sheet feeder or not based on the determination result.

These as well as other aspects, advantages, and alternatives will become apparent to those of ordinary skill in the art by reading the following detailed description with reference where appropriate to the accompanying drawings. Further, it should be understood that the description provided in this summary section and elsewhere in this document is intended to illustrate the claimed subject matter by way of example and not by way of limitation.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically illustrates an image forming apparatus according to one embodiment of the disclosure;

FIG. 2 illustrates a switching method of a paper sheet feeder according to the one embodiment;

FIG. 3 illustrates a display according to the one embodiment;

FIG. 4 illustrates a switching method of the paper sheet feeder according to the one embodiment;

FIG. 5 illustrates a display according to the one embodiment;

FIG. 6 illustrates paper sheet feeders and accumulated counts stored in a storage unit;

FIG. 7 illustrates sizes and accumulated counts stored in a storage unit; and

FIG. 8 illustrates a display according to the one embodiment.

DETAILED DESCRIPTION

Example apparatuses are described herein. Other example embodiments or features may further be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented herein. In the following detailed description, reference is made to the accompanying drawings, which form a part thereof.

The example embodiments described herein are not meant to be limiting. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the drawings, can be arranged, substituted, combined, separated, and designed in a wide variety of different configurations, all of which are explicitly contemplated herein.

The following describes an embodiment of the disclosure with reference to the drawings. In the drawings, identical reference numerals are used to the identical or corresponding parts not to repeat explanations.

With reference to FIG. 1, an embodiment of an image forming apparatus 100 according to the disclosure will be described. FIG. 1 schematically illustrates the image forming apparatus 100 according to the embodiment of the disclosure. The image forming apparatus 100 is, for example, a copier, a printer, or a multi-functional peripheral. The following describes a case where the image forming apparatus 100 is a monochrome multi-functional peripheral having a printer function, a copy function, and a facsimile function as one example.

As illustrated in FIG. 1, the image forming apparatus 100 includes an image reading unit 10, a paper feeding unit 20, a control unit 30, a storage unit 40, a communication unit 45, a conveying unit 50, an image forming unit 60, an input unit 80, a display 90, a platen 12, a document feeder 110, and a discharge unit 170.

The image reading unit 10 reads an image formed on a document G and obtains input image data. For details, the image reading unit 10 reads an image formed on the document G conveyed by the document feeder 110 or an image formed on the document G placed on the platen 12, and obtains the input image data. The document feeder 110 can sequentially convey the document G.

The paper feeding unit 20 includes a plurality of paper sheet feeders 21. The plurality of paper sheet feeders 21 includes a paper sheet feeder 21 a, a paper sheet feeder 21 b, a paper sheet feeder 21 c, and a paper sheet feeder 21 d. In this description, the paper sheet feeder 21 a, the paper sheet feeder 21 b, the paper sheet feeder 21 c, and the paper sheet feeder 21 d are sometimes collectively referred to as and described as the paper sheet feeder 21. The plurality of paper sheet feeders 21 are configured to each house sheets P. Each of the plurality of paper sheet feeders 21 is openable/closable. A user can replenish the sheet P into the paper sheet feeder 21 by opening the paper sheet feeder 21. The user can take out the sheet P from the paper sheet feeder 21 by opening the paper sheet feeder 21. The user closes the paper sheet feeder 21 after replenishing the sheet P into the paper sheet feeder 21.

The plurality of paper sheet feeders 21 each include an opening/closing detection unit 70 and a sheet information detecting unit 75. For details, the paper sheet feeder 21 a includes an opening/closing detection unit 70 a, a sheet information detecting unit 75 a, and a sheet information detecting unit 75 e. The paper sheet feeder 21 b includes an opening/closing detection unit 70 b, a sheet information detecting unit 75 b, and a sheet information detecting unit 75 f. The paper sheet feeder 21 c includes an opening/closing detection unit 70 c, a sheet information detecting unit 75 c, and a sheet information detecting unit 75 g. The paper sheet feeder 21 d includes an opening/closing detection unit 70 d, a sheet information detecting unit 75 d, and a sheet information detecting unit 75 h.

The plurality of paper sheet feeders 21 each further include a rear end regulating portion 22 and a pair of side end regulating portions 23. The rear end regulating portion 22 is in a plate shape. The rear end regulating portion 22 regulates a position of a rear end of the sheet P. The rear end regulating portion 22 is slidable. The pair of side end regulating portions 23 are in a plate shape and opposed to one another. The pair of side end regulating portions 23 regulate a position of side ends of the sheet P. The pair of side end regulating portions 23 are slidable in a direction approaching one another or a direction separating from one another. The rear end regulating portion 22 and the pair of side end regulating portions 23 move corresponding to a size and an orientation of the sheet P housed in the paper sheet feeder 21, and thus, positions of the sheets P in different sizes and orientations can be regulated.

The opening/closing detection unit 70 a, the opening/closing detection unit 70 b, the opening/closing detection unit 70 c, and the opening/closing detection unit 70 d are located in the paper sheet feeder 21 a, the paper sheet feeder 21 b, the paper sheet feeder 21 c, and the paper sheet feeder 21 d, respectively. The opening/closing detection unit 70 a, the opening/closing detection unit 70 b, the opening/closing detection unit 70 c, and the opening/closing detection unit 70 d detect openings and closings of the paper sheet feeder 21 a, the paper sheet feeder 21 b, the paper sheet feeder 21 c, and the paper sheet feeder 21 d, respectively. For details, the opening/closing detection unit 70 a, the opening/closing detection unit 70 b, the opening/closing detection unit 70 c, and the opening/closing detection unit 70 d detect the openings of the paper sheet feeder 21 a, the paper sheet feeder 21 b, the paper sheet feeder 21 c, and the paper sheet feeder 21 d, respectively. The opening/closing detection unit 70 a, the opening/closing detection unit 70 b, the opening/closing detection unit 70 c, and the opening/closing detection unit 70 d detect the closings of the paper sheet feeder 21 a, the paper sheet feeder 21 b, the paper sheet feeder 21 c, and the paper sheet feeder 21 d, respectively. In this description, the opening/closing detection unit 70 a, the opening/closing detection unit 70 b, the opening/closing detection unit 70 c, and the opening/closing detection unit 70 d are sometimes collectively referred to as and described as the opening/closing detection unit 70. The opening/closing detection unit 70 detects the opening and closing of the paper sheet feeder 21, for example, by whether a switch located in the paper sheet feeder 21 is pressed or not. For details, when the switch is not pressed, the opening/closing detection unit 70 detects that the paper sheet feeder 21 is opened. Meanwhile, when the switch is pressed, the opening/closing detection unit 70 detects that the paper sheet feeder 21 is closed.

The sheet information detecting units 75 a to 75 h detect sheet information. The sheet information indicates information regarding the sheet P housed in the paper sheet feeder 21. The sheet information is, for example, a size of the sheet P, an orientation of the sheet P, and an amount of the sheets P.

The sheet information detecting unit 75 a, the sheet information detecting unit 75 b, the sheet information detecting unit 75 c, and the sheet information detecting unit 75 d are located in the paper sheet feeder 21 a, the paper sheet feeder 21 b, the paper sheet feeder 21 c, and the paper sheet feeder 21 d, respectively. The sheet information detecting unit 75 a, the sheet information detecting unit 75 b, the sheet information detecting unit 75 c, and the sheet information detecting unit 75 d each detect a size and an orientation of the sheets P housed in the paper sheet feeder 21 as the sheet information. For details, the sheet information detecting unit 75 a, the sheet information detecting unit 75 b, the sheet information detecting unit 75 c, and the sheet information detecting unit 75 d each detect the size and the orientation of the housed sheets P based on positions of the rear end regulating portions 22 and positions of the pairs of side end regulating portions 23.

The sheet information detecting unit 75 e, the sheet information detecting unit 75 f, the sheet information detecting unit 75 g, and the sheet information detecting unit 75 h are located in the paper sheet feeder 21 a, the paper sheet feeder 21 b, the paper sheet feeder 21 c, and the paper sheet feeder 21 d, respectively. The sheet information detecting unit 75 e, the sheet information detecting unit 75 f, the sheet information detecting unit 75 g, and the sheet information detecting unit 75 h each detect an amount of the sheets P housed in the paper sheet feeder 21 as the sheet information. For example, the sheet information detecting unit 75 e, the sheet information detecting unit 75 f, the sheet information detecting unit 75 g, and the sheet information detecting unit 75 h each detect the amount of the housed sheets P based on weights of the housed sheets P.

The conveying unit 50 conveys the sheet P from the paper sheet feeder 21 selected among the plurality of paper sheet feeders 21. When a copy is executed, the sheet P in the paper sheet feeder selected among the plurality of paper sheet feeders 21 by a user is conveyed by the conveying unit 50 so as to be discharged from the discharge unit 170 via the image forming unit 60.

The control unit 30 is a hardware circuit configured of, for example, a processor such as a Central Processing Unit (CPU) and an Application Specific Integrated Circuit (ASIC). The control unit 30 controls operations of the respective units of the image forming apparatus 100 by the processor reading out and executing a control program stored in the storage unit 40. The control unit 30 controls, for example, the paper sheet feeder 21, the image forming unit 60, and the conveying unit 50.

The storage unit 40 is configured of a Hard Disk Drive (HDD), a Random Access Memory (RAM), and a Read Only Memory (ROM). The storage unit 40 may include an external memory. The external memory is a removable media. The storage unit 40 includes, for example, a Universal Serial Bus (USB) memory and a Secure Digital (SD) card as the external memory. The storage unit 40 stores various kinds of data and control programs for controlling operations of the respective units of the image forming apparatus 100. The control program is executed by the control unit 30.

The communication unit 45 can communicate with an electronic device in which a communication device that uses a similar communication method (protocol) is included. In this embodiment, the communication unit 45 communicates with an external device via a network such as a Local Area Network (LAN). The communication unit 45 is a communication module (communication device) such as a LAN board.

The external device is a device used by a user, and, specifically, is a personal computer or a tablet terminal device. In this embodiment, a user transmits a print job to the image forming apparatus 100 by operating the external device.

The image forming unit 60 forms an image on the sheet P conveyed by the conveying unit 50 based on the input image data. The input image data is, for example, a print job transmitted from the external device. Alternatively, the input image data is image data read by the image reading unit 10.

The display 90 is a display having a touch panel function that can display software buttons, and is arranged on the operation panel. Such a touch panel function can double as the display 90 and the input unit 80. The display 90 displays a confirmation image. The confirmation image is, for example, an image to confirm whether to switch the selected paper sheet feeder 21 or not.

The input unit 80 is, for example, an operation panel having the touch panel function and various kinds of hardware buttons. An instruction by a user is input to the input unit 80. The hardware buttons include a start button 81.

With reference to FIGS. 1 and 2, a description will be given of a switching method of the paper sheet feeder 21 of the image forming apparatus 100 according to the disclosure. FIG. 2 illustrates the switching method of the paper sheet feeder 21 according to the embodiment of the disclosure. Executing processes of Steps S102 to S114 illustrated in FIG. 2 switches the paper sheet feeder 21.

Step S102: the opening/closing detection unit 70 detects that the paper sheet feeder 21 is opened. The process proceeds to Step S104.

Step S104: the control unit 30 obtains first sheet information. The first sheet information indicates sheet information in a state where the paper sheet feeder 21 is opened. For details, the sheet information detecting unit 75 of the opened paper sheet feeder 21 detects a size of the sheet P, a direction of the sheet P, and an amount of the sheets P. The control unit 30 obtains the size of the sheet P, the direction of the sheet P, and the amount of the sheets P in the state where the paper sheet feeder 21 is opened from the sheet information detecting unit 75. The process proceeds to Step S106.

Step S106: the opening/closing detection unit 70 detects that the paper sheet feeder 21 is closed. The process proceeds to Step S108.

Step S108: the control unit 30 obtains second sheet information. The second sheet information indicates sheet information in a state where the paper sheet feeder 21 is closed. For details, the sheet information detecting unit 75 of the closed paper sheet feeder 21 detects a size of the sheet P, a direction of the sheet P, and an amount of the sheets P. The control unit 30 obtains the size of the sheet P, the direction of the sheet P, and the amount of the sheets P in the state where the paper sheet feeder 21 is closed from the sheet information detecting unit 75. The process proceeds to Step S110.

Step S110: the control unit 30 determines whether the sheet information has changed from before and after opening and closing the paper sheet feeder 21 or not. For details, the control unit 30 determines whether there is a change between the first sheet information and the second sheet information or not. For more details, the control unit 30 determines whether at least one of the size of the sheet P, the orientation of the sheet P, and the amount of the sheets P has changed from before and after opening and closing the paper sheet feeder 21 or not. When the control unit 30 determines that the sheet information has not changed from before and after opening and closing the paper sheet feeder 21 (Step S110: No), the process is terminated. That is, when the sheet information has not changed from before and after opening and closing the paper sheet feeder 21, it is indicated that a user closed the paper sheet feeder 21 without putting out or putting in the sheet P after opening the paper sheet feeder 21. Accordingly, it is not necessary to switch the selected paper sheet feeder 21, and therefore, the process is terminated. Meanwhile, when the control unit 30 determines that the sheet information has changed from before and after opening and closing the paper sheet feeder 21 (Step S110: Yes), the process proceeds to Step S112.

Step S112: the control unit 30 determines whether the paper sheet feeder 21 the sheet information of which has changed matches the selected paper sheet feeder 21 or not. When the control unit 30 determines that the paper sheet feeder 21 the sheet information of which has changed matches the selected paper sheet feeder 21 (Step S112: Yes), the process is terminated. When the paper sheet feeder 21 the sheet information of which has changed, that is, the paper sheet feeder 21 into or out of which a user put the sheet P matches the selected paper sheet feeder 21, it is not necessary to switch the selected paper sheet feeder 21, and therefore, the process is terminated. When the control unit 30 determines that the paper sheet feeder 21 the sheet information of which has changed fails to match the selected paper sheet feeder 21 (Step S112: No), the process proceeds Step S114.

Step S114: the control unit 30 switches the selected paper sheet feeder 21 to the paper sheet feeder 21 the sheet information of which has changed. The process is terminated.

As described above with reference to FIGS. 1 and 2, the control unit 30 determines whether the sheet information has changed from before and after opening and closing the paper sheet feeder 21 or not. The control unit 30 determines whether to switch the selected paper sheet feeder 21 or not based on the determination result. Accordingly, it is possible to switch the selected paper sheet feeder 21 to the paper sheet feeder 21 into or out of which a user has put the sheet P without the user specifying a switching destination of the paper sheet feeder 21. As a result, the paper sheet feeder 21 can be easily switched.

The control unit 30 determines whether the paper sheet feeder 21 the sheet information of which has changed matches the selected paper sheet feeder 21 or not when the sheet information has been determined to be changed from before and after opening and closing the paper sheet feeder 21. When it is determined that the paper sheet feeder 21 the sheet information of which has changed fails to match the selected paper sheet feeder 21, the selected paper sheet feeder 21 is switched to the paper sheet feeder 21 the sheet information of which has changed. Accordingly, it is possible to switch the selected paper sheet feeder 21 to the paper sheet feeder 21 into or out of which a user has put the sheet P without the user specifying a switching destination of the paper sheet feeder 21. As a result, the paper sheet feeder 21 can be easily switched.

The sheet information detecting unit 75 detects the size of the sheet P housed in the paper sheet feeder 21 as the sheet information. Accordingly, the control unit 30 can determine whether the size of the sheet P housed in the paper sheet feeder 21 as the sheet information has changed from before and after opening and closing the paper sheet feeder 21 or not. As a result, the control unit 30 can determine whether a user put in or out the sheet P or not when the user opened and closed the paper sheet feeder 21.

The sheet information detecting unit 75 detects the orientation of the sheet P housed in the paper sheet feeder 21 as the sheet information. Accordingly, the control unit 30 can determine whether the orientation of the sheet P housed in the paper sheet feeder 21 as the sheet information has changed from before and after opening and closing the paper sheet feeder 21 or not. As a result, the control unit 30 can determine whether a user put in or out the sheet P or not when the user opened and closed the paper sheet feeder 21.

The sheet information detecting unit 75 detects the amount of the sheets P housed in the paper sheet feeder 21 as the sheet information. Accordingly, the control unit 30 can determine whether the amount of the sheets P housed in the paper sheet feeder 21 as the sheet information has changed from before and after opening and closing the paper sheet feeder 21 or not. As a result, the control unit 30 can determine whether a user put in or out the sheet P or not when the user opened and closed the paper sheet feeder 21.

In the image forming apparatus 100 described with reference to FIGS. 1 and 2, when the control unit 30 determines that the sheet information has changed from before and after opening and closing the paper sheet feeder 21, the selected paper sheet feeder 21 is switched to the paper sheet feeder 21 the sheet information of which has changed, however, the disclosure is not limited to this. For example, when the control unit 30 determines that the sheet information has changed from before and after opening and closing the paper sheet feeder 21, the control unit 30 may display a confirmation image M1 on the display 90.

With reference to FIGS. 1 and 3, the confirmation image M1 will be described. FIG. 3 illustrates the display 90.

As illustrated in FIG. 3, when the control unit 30 determines that the sheet information has changed from before and after opening and closing the paper sheet feeder 21, the control unit 30 displays the confirmation image M1 on the display 90.

The confirmation image M1 is an image for confirming whether to switch the selected paper sheet feeder 21 or not. As illustrated in FIG. 3, the confirmation image M1 is, for example, an image showing a notification “Would you like to switch paper sheet feeder?”

The confirmation image M1 includes an approving button 212 and an aborting button 214. The approving button 212 and the aborting button 214 are, for example, software buttons.

When a user touches the approving button 212, the control unit 30 switches the selected paper sheet feeder 21 to the paper sheet feeder 21 the sheet information of which has changed.

Meanwhile, when the user touches the aborting button 214, the control unit 30 does not switch the selected paper sheet feeder 21.

With reference to FIGS. 1, 3, and 4, a switching method of the paper sheet feeder 21 of the image forming apparatus 100 according to the disclosure will be described. FIG. 4 illustrates the switching method of the paper sheet feeder 21 according to the embodiment of the disclosure. Executing processes of Steps S202 to S220 illustrated in FIG. 4 switches the paper sheet feeder 21. The flowchart illustrated in FIG. 4 is different from the flowchart illustrated in FIG. 2 in that the control unit 30 displays the confirmation image M1 on the display 90 before the selected paper sheet feeder 21 is switched. Steps S202 to S212 are processes similar to those of Steps S102 to S112 illustrated in FIG. 2, and therefore, an explanation for a part that overlaps will be omitted.

Steps S202 to S212: the processes similar to those of Steps S102 to S112 illustrated in FIG. 2 are performed. The process proceeds to Step S214.

Step S214: as illustrated in FIG. 3, the control unit 30 displays the confirmation image M1 on the display 90. The process proceeds to Step S216.

Step S216: the control unit 30 determines whether there is an input to switch the paper sheet feeder 21 or not. When the control unit 30 determines that there is no input to switch the paper sheet feeder 21 (Step S216: No), that is, when a user touches the aborting button 214 on the confirmation image M1, the process proceeds to Step S220. When the control unit 30 determines that there is the input to switch the paper sheet feeder 21 (Step S216: Yes), that is, when the user touches the approving button 212 on the confirmation image M1, the process proceeds to Step S218.

Step S218: the control unit 30 switches the selected paper sheet feeder 21 to the paper sheet feeder 21 the sheet information of which has changed. The process is terminated.

Step S220: the control unit 30 does not change the selected paper sheet feeder 21. The process is terminated.

As described above with reference to FIGS. 1, 3, and 4, when the control unit 30 determines that the sheet information has changed from before and after opening and closing the paper sheet feeder 21, the control unit 30 displays the confirmation image M1 on the display 90. Accordingly, a user can switch the selected paper sheet feeder 21 after the user confirms the confirmation image M1. As a result, the selected paper sheet feeder 21 can be switched corresponding to the input of the user.

With reference to FIGS. 1 and 5, a description will be given of a setting image M2. FIG. 5 illustrates the display 90. The setting image M2 is an image that sets change condition items 222 of the sheet information. The change condition items 222 of the sheet information are triggers to the process that determines whether to switch the selected paper sheet feeder 21 or not. The setting image M2 includes the change condition items 222 and check boxes 224. The check boxes 224 correspond to the neighboring change condition items 222.

The change condition items 222 include “Cassette open,” “Sheet type change,” “Sheet count change,” and “Sheet orientation change.”

When any of a plurality of the check boxes 224 is selected, a checked mark is displayed in the selected check box 224. The change condition item 222 displayed neighboring the selected check box 224 is selected. Here, “Cassette open” is selected.

For example, when “Sheet type change” is selected and the size of the sheet P is changed, the control unit 30 determines whether to switch the selected paper sheet feeder 21 or not. For example, when “Sheet count change” is selected and the amount of the sheets P is changed, the control unit 30 determines whether to switch the selected paper sheet feeder 21 or not. For example, when “Sheet orientation change” is selected and the orientation of the sheet P is changed, the control unit 30 determines whether to switch the selected paper sheet feeder 21 or not. For example, when “Cassette open” is selected and it is detected that the paper sheet feeder 21 is opened, the control unit 30 determines whether to switch the selected paper sheet feeder 21 or not.

When the control unit 30 determines that the sheet P housed in the paper sheet feeder 21 is gone, it is preferred to switch the selected paper sheet feeder 21 based on the accumulated count.

With reference to FIGS. 1 and 6, a switching method of the paper sheet feeder 21 of the image forming apparatus 100 will be described. For details, a description will be given of a case where the sheet P housed in the paper sheet feeder 21 is gone with reference to FIGS. 1 and 6. FIG. 6 illustrates the paper sheet feeder 21 and accumulated counts stored in the storage unit 40.

As illustrated in FIG. 6, the storage unit 40 stores respective accumulated counts for the plurality of paper sheet feeders 21. The accumulated count is a count of the sheets P on which images have been formed since the image forming apparatus 100 started being used to the present. In FIG. 6, cassettes 1 to 4 correspond to the paper sheet feeders 21 a to 21 d illustrated in FIG. 1. The accumulated count of the cassette 1 is 12304. The accumulated count of the cassette 2 is 24945. The accumulated count of the cassette 3 is 22030. The accumulated count of the cassette 4 is 18593.

The control unit 30 determines whether the sheet P housed in the paper sheet feeder 21 is gone or not. When it is determined that the sheet P housed in the paper sheet feeder 21 is gone, the selected paper sheet feeder 21 is switched based on the accumulated count. For details, when it is determined that the sheet P housed in the paper sheet feeder 21 is gone, the selected paper sheet feeder 21 is switched to the paper sheet feeder 21 the accumulated count of which is most among the plurality of paper sheet feeders 21. Here, the selected paper sheet feeder 21 is switched to the cassette 2 (paper sheet feeder 21 b) the accumulated count of which is the most. Accordingly, the selected paper sheet feeder 21 can be switched without a user specifying a switching destination of the paper sheet feeder 21. As a result, the paper sheet feeder 21 can be easily switched.

In the image forming apparatus 100 described with reference to FIGS. 1 and 6, the control unit 30 switches the selected paper sheet feeder 21 to the paper sheet feeder 21 the accumulated count of which is the most among the plurality of paper sheet feeders 21 when it is determined that the sheet P housed in the paper sheet feeder 21 is gone, however, the disclosure is not limited to this. For example, the control unit 30 may switch the selected paper sheet feeder 21 to the paper sheet feeder 21 that corresponds to the size of the sheet P the accumulated count of which is the most among the plurality of paper sheet feeders 21 when it is determined that the sheet P housed in the paper sheet feeder 21 is gone.

With reference to FIGS. 1 and 7, a switching method of the paper sheet feeder 21 of the image forming apparatus 100 will be described. For details, a description will be given of a case where the sheet P housed in the paper sheet feeder 21 is gone with reference to FIGS. 1 and 7. FIG. 7 illustrates sizes and accumulated counts stored in the storage unit 40.

As illustrated in FIG. 7, the storage unit 40 stores the accumulated counts for each size of the sheet P. The accumulated count is a count of images that have been formed on the sheets P since the image forming apparatus 100 started being used to the present. The sizes of the sheet P include, for example, “Letter,” “Legal,” “A4,” “A3,” and “A5.” The accumulated count of “Letter” is 3302. The accumulated count of “Legal” is 2001. The accumulated count of “A4” is 10340. The accumulated count of “A3” is 503. The accumulated count of “A5” is 6111.

The control unit 30 determines whether the sheet P housed in the paper sheet feeder 21 is gone or not. When it is determined that the sheet P housed in the paper sheet feeder 21 is gone, the control unit 30 switches the selected paper sheet feeder 21 based on the accumulated count. For details, when it is determined that the sheet P housed in the paper sheet feeder 21 is gone, the selected paper sheet feeder 21 is switched to the paper sheet feeder 21 corresponding to the size the accumulated count of which is most among the plurality of paper sheet feeders 21. Here, the selected paper sheet feeder 21 is switched to the paper sheet feeder 21 that corresponds to the size “A4” the accumulated count of which is the most. Accordingly, the selected paper sheet feeder 21 is switched without a user specifying a switching destination of the paper sheet feeder 21. As a result, the user's convenience improves.

With reference to FIGS. 1 and 8, a description will be given of a setting image M3. FIG. 8 illustrates the display 90. The setting image M3 is an image to set an operation when the sheet P housed in the paper sheet feeder 21 is gone. The setting image M3 includes change condition items 232 and check boxes 234. The check boxes 234 correspond to the neighboring change condition items 232.

The change condition items 232 include “Switch to last used,” “Switch to most used sheet,” and “Switch to most used cassette.”

When any of a plurality of the check boxes 234 is selected, a checked mark is displayed in the selected check box 234. The change condition item 232 displayed neighboring the selected check box 234 is selected. Here, “Switch to most used sheet” is selected.

For example, when “Switch to last used” is selected and the control unit 30 determines that the sheet P housed in the paper sheet feeder 21 is gone, the selected paper sheet feeder 21 is switched to the last used paper sheet feeder 21. For example, when “Switch to most used sheet” is selected and the control unit 30 determines that the sheet P housed in the paper sheet feeder 21 is gone, the selected paper sheet feeder 21 is switched to the paper sheet feeder 21 that corresponds to the size the accumulated count of which is most. For example, when “Switch to most used cassette” is selected and the control unit 30 determines that the sheet P housed in the paper sheet feeder 21 is gone, the selected paper sheet feeder 21 is switched to the paper sheet feeder 21 the accumulated count of which is the most.

While the embodiment of the disclosure has been described above with reference to the drawings (FIGS. 1 to 8), the disclosure is not limited to the embodiment described above and is implemented in various kinds of aspects (for example, (1) and (2) described below) without departing from the gist of the disclosure. The drawings schematically illustrate respective components mainly for easy understanding. Accordingly, the thickness, length, number, and similar factor of the illustrated respective components are different from the actual thickness, length, number, and similar factor for the convenience of preparing the drawings. The materials, shapes, dimensions, and similar factor of the respective components described in the embodiment described above are merely one example and are not particularly limited. Thus, they are variously changeable without substantially departing from the effects of the disclosure.

(1) While, as described with reference to FIGS. 1 to 8, the sheet information detecting units 75 e to 75 h detect the amount of the housed sheets P based on the weight of the housed sheet P, the disclosure is not limited to this. For example, the sheet information detecting units 75 e to 75 h may detect the amount of the housed sheets P based on a height of the housed sheet P.

(2) While, as described with reference to FIGS. 1 to 8, the sheet information detecting unit 75 detects the size of the sheet P, the orientation of the sheet P, and the amount of the sheets P as the sheet information, the disclosure is not limited to this. For example, the sheet information detecting unit 75 may detect a kind of the sheet P as the sheet information. The kind of the sheet P is, for example, “plain paper” and “cardboard.”

Exemplary Embodiment of the Disclosure

An image forming apparatus according to the disclosure includes a plurality of paper sheet feeders, a conveying unit, an image forming unit, and a control unit. The plurality of paper sheet feeders are configured to each house sheets. The plurality of paper sheet feeders are openable/closable. The conveying unit conveys a sheet from a paper sheet feeder selected among the plurality of paper sheet feeders. The image forming unit forms an image on the sheet conveyed by the conveying unit. The control unit controls the paper sheet feeder, the image forming unit, and the conveying unit. The plurality of paper sheet feeders each include an opening/closing detection unit and a sheet information detecting unit. The opening/closing detection unit detects opening and closing of the paper sheet feeder. The sheet information detecting unit detects sheet information. The sheet information indicates information regarding a sheet housed in the paper sheet feeder. When the opening/closing detection unit detects that the paper sheet feeder is closed after detecting that the paper sheet feeder was opened, the control unit determines whether the sheet information has changed from before and after opening and closing the paper sheet feeder or not. The control unit determines whether to switch the selected paper sheet feeder or not based on the determination result.

Effects of the Disclosure

With the image forming apparatus according to the disclosure, a paper sheet feeder can be easily switched.

While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims. 

What is claimed is:
 1. An image forming apparatus comprising: a plurality of paper sheet feeders configured to each house sheets, the plurality of paper sheet feeders being openable/closable; a conveying unit that conveys a sheet from a paper sheet feeder selected among the plurality of paper sheet feeders; an image forming unit that forms an image on the sheet conveyed by the conveying unit; and a control unit that controls the paper sheet feeder, the image forming unit, and the conveying unit, wherein the plurality of paper sheet feeders each include: an opening/closing detection unit that detects opening and closing of the paper sheet feeder; and a sheet information detecting unit that detects sheet information, wherein the sheet information indicates information regarding a sheet housed in the paper sheet feeder, and when the opening/closing detection unit detects that the paper sheet feeder is closed after detecting that the paper sheet feeder was opened, the control unit: determines whether the sheet information has changed from before and after opening and closing the paper sheet feeder or not, and determines whether to switch the selected paper sheet feeder or not based on the determination result.
 2. The image forming apparatus according to claim 1, wherein when the sheet information has been determined to be changed from before and after opening and closing the paper sheet feeder, the control unit determines whether the paper sheet feeder the sheet information of which has changed matches the selected paper sheet feeder or not, when the paper sheet feeder the sheet information of which had changed has been determined to fail to match the selected paper sheet feeder, the control unit switches the selected paper sheet feeder to the paper sheet feeder the sheet information of which has changed.
 3. The image forming apparatus according to claim 1, further comprising a display that displays a confirmation image, wherein when the sheet information has been determined to be changed from before and after opening and closing the paper sheet feeder, the control unit displays the confirmation image on the display, and the confirmation image is an image to confirm whether to switch the selected paper sheet feeder or not.
 4. The image forming apparatus according to claim 1, wherein the sheet information detecting unit detects a size of a sheet housed in the paper sheet feeder as the sheet information.
 5. The image forming apparatus according to claim 1, wherein the sheet information detecting unit detects an orientation of a sheet housed in the paper sheet feeder as the sheet information.
 6. The image forming apparatus according to claim 1, wherein the sheet information detecting unit detects an amount of sheets housed in the paper sheet feeder as the sheet information.
 7. The image forming apparatus according to claim 1, further comprising a storage unit that stores an accumulated count of the sheet on which an image is formed, wherein the control unit: determines whether the sheet housed in the paper sheet feeder is gone or not, and switches the selected paper sheet feeder based on the accumulated count when the sheet housed in the paper sheet feeder has been determined to be gone.
 8. The image forming apparatus according to claim 7, wherein the storage unit stores the accumulated counts for the respective plurality of paper sheet feeders, the control unit: determines whether the sheet housed in the paper sheet feeder is gone or not, and switches the selected paper sheet feeder to a paper sheet feeder the accumulated count of which is most among the plurality of paper sheet feeders when the sheet housed in the paper sheet feeder has been determined to be gone.
 9. The image forming apparatus according to claim 7, wherein the storage unit stores the accumulated counts for each size of a sheet, and when the sheet housed in the paper sheet feeder has been determined to be gone, the control unit switches the selected paper sheet feeder to a paper sheet feeder that corresponds to a size of a sheet the accumulated count of which is most among the plurality of paper sheet feeders. 